Drive for home recorders



June 19, 1945. l l. l.; STEPHAN y .2,373,509

DRIVE FOR HOME RECORDERS June 19, 1945. l.. STEPHAN DRIVE FOR HOMERECORDERS Filed Jan. 7, 1942 2 sheets-sheet 2 Patented` June 19, 1945OFFICE 2,378,509 DRIVE FoRHoME asoommns Ingo L. stephan, nennen,

Radio and Television Pa., a corporation of Corporation, Delaware N. J.,assignor to Philco Philadelphia,

Application January 7, 1942, Serial No. 425,934

I Cl. 274-13) 29 Claims.

The current created a demand for a recording apparatus of the inventionis to mechanism for driv- The principal'object of provide a simple,eicient reference being panying drawings, o! which: v

Fig. 1 is a. vertical elevation, with certain' parts shown in section,of arecording device constructed in accordance with this invention andapplied to a conventional phonograph device;

Fig. 2 is looking upwardly at the under side of the driving and lockoutunit forthe recording s'tyl l Figs. 3 and 4 are detached perspectiveviews of various parts of the assembled device shown inFlg.2;and

Fig. 5 is an enlarged sectional view illustratng a detail o1' theinvention. v

Referring to the drawings, there is shown in l1ig. 1 a portion of aconventional phonograph omprising a base member I0 having a turntableits inner end the hub I mounted thereon for rotation at a uniformisarranged to be table.

In accordance with conventional practice, a

rotated by' and with the turnrecording unit comprising a pivoted styluscarryingarm i3, which supports an electro-acoustic transducer orcartridge element I4, are provided. The cartridge [4. carries A drivingarm I9 the lower end of shaft chronism with movement of the arm I3.Thus.

is applied to the cartridge I4, the stylus I5 will be caused tooscillate laterally, in addition to its general groove-cutting motion bythe arm I3, in a manner to cause audio frequency undulations to beformed in the sound groove.

Considering now the means for rotating the driving arm I9, as shown inFigs. 2, 3, and 4, a sub-base 20 is provided for supporting certainelements of the driving unit. The sub-base 20 is supported, with respectto base I0, by the post I 6 and by one or more relatively spaced screwfastenings 2l. Pivotally secured at 22 to the sub-base 20, is a swingplate 234 which has an 20, tends to rotate the swing v(as seen in Fig.2) about its On thev swing plate 23. there is a pivot stud 26. whichcarries a hub member 'IA (see Fig. 4). At

an electrical signal through an opening ward rotation of ratchet v29,which is secured slippage and a unilateral clutch plate 30, which willbe described hereinafter.

Loosely mounted, for free rotation, on an annular stepped portion of thehub 21, between one ofthe steps of said hub and the lratchet wheel 28,is an,V actuating lever 3|, which is provided with a vertically-offsetportion 32 extending up in base plate I (see Fig. 1). The free end ofthe lever 3| is provided with a cam follower, in the form of a roller 33which bears against an edge cam 34.

The cam 34 is preferably formed on or secured to the central hub of theturntable II, so as'to rotate therewith. As shown in Fig. 2, the cam 34may be merely a circular disc arranged eccentrically of the axis ofrotation of the turntable.

On that side of the lever 3|, opposite the driving lever 32, is pivoteda driving pawl 35, which is biased by a Spring 36 into engagement withthe teeth of the ratchet wheel 28. A spring 31 operating between thelever 3| and the swing plate 23 serves to maintain the cam follower 33in continuous engagement with the cam 34 during operation of the device.

By reason of the above construction, the actuating lever 3| willoscillate freely about the hub 21, in timed relation to the rotation of.the turntable II, causing the pawl 35 to rotate the ratchet wheel 28and consequently the hub 21 step by step in one direction. If the cam 34is an eccentrically-mounted circular ratchet mechanism will advance thehub y21 during substantially one half of each revolution of theturntable and during revolution, the unilateral clutch plate 3D willengage the cork disc 29 and prevent retrograde movement of the ratchetwheel 2B and hub 21.

As shown in Fig. 3, the clutch plate 30 comprises a thin metal platehaving. numerous resilient teeth Aor serrations 38, which are cut in theclutch plate plane thereof at an angle thereto. These serrations areinclined, as shown, -to permit free forwheel 28, by the pawl 35, but anytendency for rearward movement of the ratchet wheel will be preventedHby the serrations biting into the adjacent face of cork disc to theratchet wheel 28. Further in accordance with this construction,

'the hub 21 is provided with a V shaped circumferential groove 39. Thelower ange forming. one of the convergent side walls of the groove 39,has been removed in Fig. 2 so as to show more clearly the operation ofthe mechanism. The driving arm I9 terminates in an arcuate portion 40having an outer arcuate edge, concentric to the axis of the stud shaftI1, and which, as shown in Fig. 5, contacts beveled surfaces 39a and 39hof the groove 39 (Figs. 1 and 2). The upper and lower edges 40a and 40hof the sector portion 4D are suitably chamfered to make a tightsurfaceto-surface contact between the sector member 40 and the groovedhub 21,

tween said edges and the converging side walls of the V-shaped grooveobviates the possibility of insures that oscillation of the actuatinglever 3 I, and consequent intermittent rotation of the hub 21, willeffect intermittent rotation of the driving arm I9, the shaft I1, andthe stylussupporting arm |3. Accordingly, the stylus I will be movedacross the face' of manner to cut a generally spiral sound groovetherein.

In apparatus of the above type it is most dedisc, as shown, the yunder'pressure of the' spring 25. This wedging drivingengagementbesirable to mount the drive means permanently in associationwith the phonograph and under such circumstances it is necessary toprovide a form of lock-out to prevent operation of the drive for ltherecording mechanism during use of the turntable for normal reproducingoperation of the phonograph. To this end, the actuating lever 3| isprovided with a pin or lug 4I, and the outer end or tip portion 42 ofthe segmental extension of the driving arm I9 is provided with a pair ofnotches 43 and 44. These parts are so arranged that when thestylus-supporting arm I3 has been swung. clockwise to an extreme outeror off position, clear of the turntable II, the driving arm I9 willlikewise be in its extreme off position. In such position of the segment40, the pin or other abutment 4| will be located in the indexing notch43, while the clearance notch 44 will lie adjacent the groove 39 of thedriving pinion portion of the hub 21. However, the notch 44 issufficiently deep to prevent engagement of the outer edge of the segment49 with the convergent side walls of the groove 39. Moreover, when thedriving arm I9 and its segmental end 40, are swung to the off position,a cam surface 41 on the outer edge of the segment 49, between theclearance notch 44 and the indexing or lock-out notch 43, engages 30 andbent outwardly from the is a spring 55 which maintains record D in a thelock-out pin 4| and swings the actuating arm 3| about its pivot 26 untilthe cam follower 33 is clear of the actuating cam 34 on the turntableII. Accordingly, during use of the turntable II in normal reproducingoperation of the phonograph there will be no transmission of motion tothe stylus arm I3, etc., through the drive mechanism.

Upon movement of the stylus arm I3 and driving arm I9, as when thestylus I5 is manually placed on and adjacent the outer edgeof a recordD, the indexing notch 43 will move laterally away from pin 4I therebyreleasing the driving means and the stylus from the lock-out means andthe drive will again become operative to move the stylus arm I3 acrossthe face of the record D. After the recording has been made, the stylusarm I3 will be raised and manually swung to its ofi position, which, ofthe grooved fac'e of the record, simultaneously( returning the drivingarm I9 to the starting position shown in Fig. 2.

If desired, a phonograph-recording changeover switch 45 may be provided.As shown in Fig. 2, the switch 45 may conveniently be actuatedautomatically by the driving arm I9 when in its off position.

The swing plate 23 is provided with a shouldered pin 5I which passesthrough and operates in a slot 52 formed in the su -base 20 to stabilizethe swing plate 23 and the rotary elements of the driving unit carriedthereby as the spring 25 moves the plate 23 about its pivot to effectfirm driving contact between the chamfered edge of the segment 40 andthe driving pinion formed by the groove 39 in the hub 21. i

As shown in Fig. l, the pivot stud 26 carrying hub 21, clutch disc 30,and ratchet wheel 28, is provided, beyond the lower end of the hub 21,with a washer 53 and lock nuts 54, 54. Between the washer 53 and thelower end of the hub 21 thehub 21 with 28 thereon and the clutch discsbut yielding axial relationship the ratchet wheel 29 and 30 in rm toeach other to permit proper operation of the clutch during retrogradeoscillation of the actuating lever 3|.

It will be clear from the above described construction that I haveprovided a novel, simple,

inthe present instance, is clear for cutting a sound lrecord, a drivingarm -predetermined Ymined plane, a driving 'an axis-substantiallyperpendicular to the plane ment between said driv 'determined relationto the and eilicient drive and lock-out mechanism for recording'apparatus, but my invention as above described maybe modiiiedand shouldbe considered limited only by the following claims.

For assembly purposes, they actuating lever 3| is provided with a slot50 and the swing plate 23 is provided with a projection 46 which extendsinto the slot 50, the opposite ends 48 and 49 of which hold the lever3|, and parts associated therewith, within certain limits prior to thedriving unit shown in Fig. 2 being installed on the phonograph.

Iclaim: l. In a recording apparatus employing a stylus groove in arotating phonograph record, a stylus-supporting arm mounted for pivotalmovement connected to and adapted concurrently with saidstylus-supporting arm, a rotatable member engageable directly with saiddriving arm, and power transmitting means including rotary input forpivotal movement for cutting a sound groove in a rotating phonographrecord, a stylus-supporting arm operable parallel to the face of therecord, a' driving arm and having an arcuate edge disposed beneath therecord -and connected to said stylus-supporting arm and having anarcuate edge movable in a.

plane, a. driving member rotatable about an axis substantiallyperpendicular to the plane in which said edge of said driving arm foreffecting traverse of the stylus across the face connected to saidstylus-supporting arm and having an arcuate edge movable in a'predetermember rotatable about in which saidedge of said driving armmoves silient means for parallel to the face to the and frictionallyengageable with said driving arm,

movable means supper g said driving member, resilient control meansforsaid movable supporting means and affording relative lateral movementbetween said driving arm and said driving member to effect flrmfrictional driving engageing arm, and means carried by said movablesupport for rotating said driving member in prerotations of said reco'rdfor effecting traverse of the stylus across the face of the record. Y

4. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phonograph record, astylu's-supporting armoperable" of the record, a driving arm stylus-supporting arm and edgemovable in a predeterparallel to the face connected to said having anarcuate mined plane, a driving .an axis substantially perpendicular tothe'plane in which said edge of said driving arm moves and irictionallyengageable with said driving` member and said drivmember rotatable aboutf connected to said parallel tothe face 5; In a recording apparatusemploying a stylus for cutting a sound groove in graph record, astylus-supporting arm operable said edge of said driving arm moves andfrictionally engageable with said edge, resilient means urgingv saidmember into iirm frictional driving engagement with said edge, and

means for rotating said member lto effect travof the record.

erse of the 'stylus across the face 6. In a recording apparatusemploying a stylus for cutting a sound graph record, a stylus-supportingarm operable parallel to the face of connected to said stylus-supportinarm, a segmental extension on said drivingarm and having an arcuateedge, a driving member, means supporting said member with its axis ofrotation substantially perpendicular to the plane of said drivtraverseof the stylus across the face of the record. l

7. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phonograph record, a stylus-supporting arm operableparallel to the face of the record, a driving arm connectedl to saidstylus-supporting arm, a driving member engageable with said drivingarm, means for rotating said member to eiect traverse oi the stylusacross the face of the record including a ratchet wheel said member, anactuating lever freely rockable with respect to the ratchet wheel, apawl pivoted to said lever and engageable with said ratchet tate saidmember.

8. In a recording apparatus employing a stylus for cutting a soundgroove in arotating phonograph record, a stylus-supporting arm operableof the record, a driving arm connected to said stylus-supporting arm andhaving an arcuate edge, a driving member frictionally engageable withlsaid edge, and means for wheel, and means for rocking said lever to rol'rotating said member in predetermined relation A graph record, astylus-supporting arm operable parallel to the face of :the record, a.driving arm connected to said stylus-supporting arm and havgroove in arotating phono-` the record, a driving arm drivingly-connected to allyengageable with said edge, resilient means supporting said member toeffect firm frictional driving engagement between said member and saiddriving arm, and means for rotatingisaid member comprising a ratchetwheel carried by 5 said resilient means and drivingly connected to saidmember, an actuating lever carried by said resilient means, a pawlpivoted to said lever and engageable with said ratchet Wheel, and cammeans for rocking said lever in timed relation to l the rotations ofsaid record.

10. In a recording apparatus employing` a stylus for cutting a soundgroove in a rotating phonograph record, a stylus-supporting arm operableparallel to the face of the record, a driving arm l connected to saidstylus-supporting arm, a segmental extension on the outer end of saiddriving arm having an arcuate edge, a driving pinion frictionallyengageable with said arcuate edge of the segmental extension of saiddriving arm, 2o

resilient 'means supporting said pinion to eiect firm frictional drivingengagement between said pinion and said driving arm, a ratchet wheeldrivingly connected to said pinion, an actuating lever,

a pawl pivoted to said lever and engageable with said ratchet wheel, acam follower on said lever, and, an eccentric cam rotatable with saidrecord for oscillating said lever to eie'ct traverse of the stylusacross the face of the record.

l1. In a recording apparatus employing a stylus s() for cutting a soundgroove in a rotating phonograph record, a base structure, astylus-Supporting arm pivotally mounted on said base, a driving armconnected to said stylus-supporting arm for swinging movement therewith,a swing plate pivoted to said base structure, a driving member rotatablymounted in said swing plate with its axis o rotationsubstantially,perpendicular to the plane of said driving arm anddisposed for fricmeans resiliently swinging said plate to effect saidfrictional driving engagement, and means carried by said swing plate forrotating said driving member.

12. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phonograph record, a base structure, astylus-supporting arm pivotally mounted on said base structure,

a driving arm connected to said stylus-supporting arm for swingingmovement therewith, a swing 5 plate pivoted to said base structure, apinion rotatably .mounted in said swing plate for irictional drivingengagement with an arcuate edge of said drivin-g arm, means resilientlyswinging'said plate to eiect said frictional driving engagement, anactuating lever mounted on said swing plate for oscillation about theaxis of said pinion, a ratchet 'wheel drivingly connected to saidpinion, a pawl pivoted on said actuating lever and engageable with saidratchet wheel; an actuating cam rotatable with said record, and a camfollower on said actuating lever engageable by said cam forintermittently rotating said pinion.

13. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phono- 6* graph record, a pivotally mountedstylus-supporting arm, a driving arm connected to said stylussupportingarm for swinging movement therewithUa rotary pinion for operating saiddriving arm, an oscillatory lever orturning said pinion,

a ratchetv wheel drivingly connected to said pinion, a pawl onsaid leverand engageable with said ratchet wheel, means for rocking said lever torotate said ratchet wheel and said pinion intermittently, a rotaryclutch member 'connected 75 to said ratchet wheel `for rotationtherewith, and

, a stationary clutch member for cooperation with said rotary clutchmember to prevent retrograde the face of the record, an. arcuate sectormember drivingly connected to said arm, rotatable drive means inengagement with said sector member, an eccentric drive member, and meanscomprising a lever oscillatable'by said eccentric drive member,` andhaving a driving and a return stroke, said last means being constructedand arranged to actuate said rotatable drive means during the drivingstroke and thereby effect intermittent advance of said sector memberwith respect to said drive means.

15. In a recording apparatus employing a stylus i'or cutting a soundgroove in a rotating phonograph record, a stylus-supporting arm operableparallel to the face ofthe record, a second arm drivingly connected tosaid stylus-supporting arm and having a chamfered arcuate edge, a.driving pinion having a circumferential groove with converging sidewalls formed therein, means maintaining said side walls in wedgingcontact with means actuating said driving member in predetional drivingengagement with said driving arm, 40

termined relation to the rotations of said record for eiiecting traverseo the stylus across the face of the record, and means operable by saiddriving arm for-moving said driving member from and locking said drivingmember out of driving contact with said driving arm:

l'1`l In a recording apparatus employing a stylus 4 `for cutting a soundgroove in a rotating phonograph record, a stylus-supporting arm operableparallel to the face of the record, a driving arm connected to saidstylus-supporting arm, a driving member engageable with said drivingarm,

primary actuating means rotatable with said record, complementary meansoperated by said primary means for rotating said member to eect f'traverse of the stylus across the face of the record, and cooperatingmeans carried by said driving arm and said complementary -meansrespectively for locking said complementary means out of engagement withsaid primary actuating means when said stylus is moved to a position ofrest with respect to said record.

18. In a recording apparatus employing a Stylus.

for cutting a sound groove in a rotating phonograph record, astylus-supporting arm operable parallel to' the face of therecord, meansfor effecting traverse of said stylus across the face of the record byits supporting arm comprising. a driving arm connected to saidstylus-supporting' arm and having an arcuate edge movable in apredetermined plane, a driving member rotatable about an axissubstantially perpendicular to the A.plane in which said edge of saiddriving arm moves and engageable with said driving arm.

ymeans. actuating said driving member in predetermined relation totherotations of said record,

ymoved to a and means responsive to said parallel movement of saidstylus-supporting arm from an operative position to a arm by saidactuating means.

19. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phonosaid primary actuating means.

20. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phonograph record, a stylus-supporting arm operableparallel to the .face of position of rest with respect to said record.

22. In a recording apparatus employing a stylus for cutting a soundgroove in a rotating phonograph record,.a stylus-supporting arm operableparallel to the face of the record, an arm'in driving relation 4to saidstylus-suprmrting arm, a

and an index notch on engageable with said abutment to hold rsaid ca4'follower out of Vcontact with said cam when the stylus-supporting armis moved 23. In a recording apparatus employing a stylus ,'or cutting asound grove in a rotating phono- :raph record, a stylus-supporting armoperable 75 parallel to the face oi' the record, a driving armdisengagement between said pinion and said driving armv when saidstylus-supporting arm is moved from an operative to a rest positionrelative to said record.

'26. A control unit for in synchronization with the rotations of therecord, and an intermediate element carried by said swing frame andintermittently operable by said y impulse element and operativelyconnected to said rotary element to impart intermittent rotation theretoand consequent step -by s'p progression to said stylus through saiddriving' element.

28. A control unt for a groove cutting stylus engaging a rotating recordin a phonographic recorder having a driving element for eflectinglateral progression of the stylus across the record, said unitcomprising a swing frame, a shaft rotatably mounted in said swing frame,a rotary element secured to said shaft and engageabie with said drivingelement, a reciprocable impulse element carried by said swing frame `andoperable in synchronization with the rotations of the record, and anintermediate element secured to said shaft and intermittently operableby said impulse element and operatively connected to said rotary elementto impart intermittent rotation thereto and consequent step by stepprogression to said stylus through said driving element.

29. A control unit for a groove cutting stylus engaging a rotatingrecord in a phonographic recorder having a driving element for effectinglateral progression of the stylus across the record, said unitcomprising a swing frame, a shaft rotatably mounted in said swing frame.a rotary element secured to said shaft and engageable with said drivingelement, a reciprocable impulse element carried by said swing frame andoperable in synchronization with the rotationsv of the record, anintermediate element secured to said shaft and intermittentlyoperable-by said impulse element and operatively connected to saidrotary element to impart intermittent rotation thereto and consequentstep by step progression to said stylus through said-driving element,and antiretrogressive means anchored to said frame and engageable withone of said elements on said shaft to prevent retrogression of saidrotary1 element.

INGO L. STEPHAN.

